The Maryland Democrat says Carroll County resident Carole Price is his guest for the event Tuesday in Washington.

Price's 13-year-old son John was accidentally shot and killed in 1998 by a 9-year-old neighbor. Price helped lead a successful effort in 2000 to require internal, mechanical trigger locks on handguns sold in Maryland.

She helped organize Maryland's participation in the Million Mom March that same year.

Price is a former president of Marylanders Against Handgun Abuse.

She is involved in the ASK Campaign, which urges parents to ask their neighbors if they have a gun in the house before sending their children there to play.